Chapter I: On True, False, and Perplexed Conscience

33. Definition. - True conscience is that which from true principles rightly concludes that something is lawful or unlawful, which truly is such; as if someone from this true principle: it is not lawful to obey parents commanding sin, should infer: therefore it is unlawful for me to perpetrate this theft which they command me. - True conscience, strictly speaking, is not the same as right conscience, although sometimes they are used promiscuously; for true is said according to what is, but right according to what is apprehended. Namely, true is that which really in itself is such; but right is that which is done according to the rules of prudence. Hence right conscience can be predicated even of him who labors under an invincibly false conscience; for he acts prudently, since he acts from an intimate and insuperable persuasion. You have an example in him who, from invincible error, thinks that it is not a fast day when it truly is. His conscience is not indeed true, but nevertheless is right.

34. - False (or erroneous) conscience is that which dictates as true and lawful that which nevertheless in itself is false and unlawful.

A twofold false conscience is distinguished: invincible and vincible. Invincible is that which morally cannot be overcome, since no thought or doubt of error, not even in the confused, comes into the mind of the one acting while he places the action or its cause. But vincible is that which the one acting can and ought to overcome, because a) he has already noticed the error, or at least doubts about it, and b) at the same time notices the obligation of overcoming it; nevertheless c) he neglects to overcome it. Thus conscience is invincibly erroneous in him who, not even confusedly noticing that it is a fast day, eats meat; but vincibly erroneous in the same person if, suspecting that it is a fast day, he notices the obligation of inquiring about the matter, and nevertheless neglects to inquire.

35. Principles. - I. True conscience, commanding, must always be followed. For conscience is the herald of law, or of God, in the case truly commanding; therefore he who refuses to obey true conscience refuses to obey God Himself.

II. Invincibly erroneous conscience, whether commanding or prohibiting, must likewise be followed in every case. It is proved: a) From Sacred Scripture: Everything that is not from faith (according to the dictate of conscience) is sin.¹

b) From reason. For the object of the will is good and evil, not in whatever way, but formally insofar as it is in the apprehension of the intellect; whence, when the intellect apprehends something as a moral good that is necessary and commanded, although in reality it is not good nor commanded, indeed is evil and prohibited, the will, by rejecting it, consents to a transgression of law. Again, if the intellect apprehends something and proposes it to the will as morally evil and prohibited, although in reality it is not evil nor prohibited, indeed is good or permitted and even commanded, the will, by embracing it, consents to an evil and prohibited object, and therefore sins. Thus he who thinks that there is a fast when there is not, on account of erroneous conscience sins against the precept if he does not fast.

III. Invincibly erroneous conscience permitting exempts from every sin, because there can be no sin where no malice is apprehended. Thus he does not sin who lies in order to free his neighbor from danger of life, invincibly thinking that this is lawful for him in the case.

IV. It is not permitted to follow a vincibly erroneous conscience, whether permitting or commanding, because, since by hypothesis the error is vincible, whoever acts with such a conscience errs voluntarily. Nor is it permitted to act against it when it is commanding or prohibiting, because by acting thus he does that which he judges prohibited, and therefore sins.

Therefore before the action that conscience must be laid aside through inquiry into the truth. Thus he who with some doubt thinks that he must lie or steal in order to assist his neighbor cannot follow such a conscience nor act against it; but he must, if he can, inquire, lay it aside, and afterwards act; for such error is vincible.

Nevertheless, one acting against a vincibly erroneous conscience does not incur penalties latae sententiae against transgressors of that law against which by error he thinks that he is acting; because penalties are inflicted on transgressors of the law truly, not putatively. Thus, for example, he who strikes a layman, thinking him to be a cleric, does not incur excommunication.

36. Practical admonitions. A) A confessor will be able more easily to judge that the conscience of his penitent was invincibly erroneous:

1° If the thing ignored is not concerning the first moral principles, or concerning conclusions proximately connected with them; for these are inscribed by nature itself in the hearts of all. Hence, if someone admits that in his past life he perpetrated openly dishonorable things, but did not have them as sins, do not easily believe him, unless the matter is of a sin committed by a child or an uneducated person, or with some circumstance apparently making it honorable, and not prolonged for a longer time.

2° If it is not concerning the obligations of one's own state; for this ignorance is ordinarily culpable in its cause. Hence St. Thomas teaches that a judge who errs in passing sentence is not excused on the ground that he is ignorant of laws which, by reason of his office, he was bound to have learned.¹ - But by length of time vincible ignorance can become invincible. For just as it happens that you forget those things which you once learned, so a fortiori it happens that the memory of your ignorance entirely slips away from you; in which case, indeed, new errors and errors of good faith will not be culpable in themselves, but in the cause, or as effects of culpable ignorance, so long as the cause itself has not been retracted, at least indirectly, through penance.

3° If the penitent is sufficiently diligent and accurate in fulfilling those things which are wont to be performed by others of the same condition; or, if noticing that through ignorance he has violated a precept, he grieves and is saddened; for through these things his good faith is rightly presumed.

B) Erroneous conscience can in no way bind unless the matter is placed in the free choice of man. Hence they do not sin who unwillingly are agitated either by obscene imaginations, or by blasphemous and heretical thoughts, although they falsely believe that they are either giving consent to these things, or even by error judge it a great fault to be touched by thoughts so horrible.

C) Great prudence is required in the theologian, preacher, confessor, instructor of boys, nurses, parents, in a word in all those who must direct others, lest by exaggerating erroneous conscience they induce it in them. Yet do not understand this in such a way as if, when preaching, it were not permitted to you with more vehement speech to censure certain things which, although they are not in themselves mortal, are exceedingly dangerous. See St. Alph. L. III. n. 55. § cum ego munus, etc.

37. - Perplexed conscience is called that by which someone thinks that he sins whichever of two incompatible precepts he neglects. Such would be the conscience, for example, in him who, assisting a sick person, thinks that he would sin both if he should leave the sick person in order to be present at Mass, and if, conversely, he should omit Mass in order to remain at home in the care of the sick person.

He who labors under a perplexed conscience, if he can suspend the action without grave harm, is bound to suspend it until he has consulted experts; for each person must avoid that by which he thinks God is offended. But if he cannot suspend his action, as ordinarily happens, he is bound to choose the lesser evil; for the will cannot tend into that which appears the greater evil, because thus it would freely choose this excess of malice. But if he cannot discern which is the lesser evil, then whichever part he chooses, he does not sin; because he is indeed free physically by reason of the act, but he is not free morally by reason of sin; for there can be no sin in that which in no way can be guarded against.